scholarly journals LOCAL EXHAUST VENTILATION WITH EJECTION OF EXPLOSIVE SUBSTANCES AND RECIRCULATION OF PURIFIED AIR

2021 ◽  
Vol 6 (2) ◽  
pp. 28-37
Author(s):  
A. Shashin ◽  
R. Sheps ◽  
A. Seminenko ◽  
V. Minko
Keyword(s):  
Gas Flow ◽  
Operation Mode ◽  
Experimental Studies ◽  
Operating Costs ◽  
Local Exhaust Ventilation ◽  
Industrial Enterprises ◽  
Exhaust Ventilation ◽  
Cleaning Device ◽  
Harmful Substances ◽  
Air Exchange

Exhaust ventilation systems in industrial enterprises and facilities with the use of harmful substances largely determine the air exchange in the workplace to ensure normalized sanitary and hygienic conditions and operating costs. Local exhaust ventilation of explosive harmful substances is of particular importance for effective air exchange in such rooms, since their localization, suction and transportation are subject to increased requirements. The paper presents the results of analytical and experimental studies of the operation mode of a complex local exhaust device with a gas ejector for extraction explosive harmful chemicals from shelters, ensuring their effective localization, purification and recirculation of air. The boundary conditions and assumptions for calculating the characteristics of the processes of gas flow ejection, purification of technological emissions and recirculation of the purified gas flow, determined on the basis of the analysis of previously performed studies and experimental work, are given. The conditions of rational ratios device settings of extraction of emissions sources of substances that parameters of the ejector and cleaning device emission, which is achieved economic and environmental efficiency of the installation and excludes the volatile situation on the threat of chemical enterprises and objects.

scholarly journals Development of effective methods and means of normalizing the atmosphere of working zones of open-cast mines

2020 ◽  
Vol 34 ◽  
pp. 29-40
Author(s):  
V. Nalyvaiko ◽  
V. Konovaliuk
Keyword(s):  
Experimental Studies ◽  
Negative Temperature ◽  
Water Jet ◽  
Lower Atmosphere ◽  
Water Volume ◽  
Irrigation Systems ◽  
Harmful Substances ◽  
Technical Solutions ◽  
Open Cast ◽  
Air Exchange

The search for technical solutions for effective air exchange in the space of deep open-cast mines. Since intensive air exchange is necessary to remove and disperse harmful impurities from the open-cast mines, improvement can be achieved mainly by intensifying natural air exchange based on phase transformations of liquids in the lower atmosphere of the working zones of the open-cast mines by creating a positive or negative temperature gradient. New technical solutions are considered that provide support for the sanitary-hygienic parameters of the atmosphere of the deep open-cast mines at the normative level. The formation of an ascending gas stream by a cascade explosion of a fuel-air mixture has the greatest efficiency. The proposed method allows for the implementation of a pulsed ventilation mode with a power of the outgoing air flow of more than 1010 W with a blasting fuel mass of 30 tons. It has been established by analytical and experimental studies that it is advisable to use pulsed fine irrigation systems to intensify air exchange in a deep open-cast mines, using the double effect, ventilating gaseous working zones and cleaning them from harmful substances with the help of a fine aerosol freely floating in space. It is also advisable to use such facilities to reduce peak loads on emissions of harmful substances from the open-cast mines into the environment and to normalize the composition of the atmosphere of the deep open-cast mines. Significant peak emissions of harmful impurities in open-cast mines include mass explosions and situations involving the creation of internal inversion zones. In a computational experiment, there are two water guns: big gun (the water jet range is 200 m, water volume per one cycle is 1000 dm3) and small gun(the water jet range is 100 m, water volume per one cycle is 200 dm3). The results of the experiment indicate greater efficiency in the use of a large water gun for airing the lower horizons of the deep open-cast mines. The use of pulsed fine irrigation systems will allow for carrying out internal technological work at a depth of more than 500 meters using a motorized ore delivery system to transfer points of cyclic-flow technology.

scholarly journals Influence of the scheme of air exchange organization in the room on the efficiency of the air-jet hood of the heat treatment chamber

2020 ◽  
Vol 224 ◽  
pp. 03026
Author(s):  
Tatyana Zhilkina ◽  
Viktor Pukhkal ◽  
Vladislav Pankov
Keyword(s):  
Heat Treatment ◽  
Software Package ◽  
Computational Experiment ◽  
Ventilation System ◽  
Exhaust Hood ◽  
Local Exhaust Ventilation ◽  
Exhaust Ventilation ◽  
Air Jet ◽  
Calculation Results ◽  
Air Exchange

Local exhaust ventilation allows maximizing the localization of hazards with minimum values of air exchange in the room. For the study, the design of a local exhaust in the form of an air-jet hood at an open doorway of the UKM Classic M 2005 chamber by Mauting was adopted. Geometric models have been developed, including a heat treatment chamber, a room from which the chamber is loaded, a supply and exhaust hood over the door from the chamber to the room, and a supply air duct with air distributing devices. The results of a computational experiment on modeling the operation of the local exhaust ventilation system of the heat treatment chamber are presented. The STAR-CCM+ software package was used as a calculation program. The calculation results were analyzed. The influence of the air exchange scheme (location of the supply devices) in the room on the efficiency of the local exhaust devices (supply and exhaust hood) has been established.

scholarly journals Influence of local exhaust ventilation parameters on the quality of the room’s air environment

2020 ◽  
Vol 175 ◽  
pp. 11020
Author(s):  
Alexey Shashin ◽  
Roman Sheps ◽  
Dmitry Lobanov ◽  
Alexander Mershiev
Keyword(s):  
Air Quality ◽  
Experimental Studies ◽  
Source Surface ◽  
Air Velocity ◽  
Surface Source ◽  
Local Exhaust Ventilation ◽  
Exhaust Ventilation ◽  
Mass Transfer Processes ◽  
Harmful Emissions

The article considers the influence of local exhaust ventilation parameters on the quality of the room’s air environment. On the basis of experimental studies, dependencies were established that determine the effect of mass transfer processes occurring in the local exhaust ventilation shelter on air quality in a room working area. The influence of a flat plate installed in the lower part of technological opening of a shelter that prevents incoming air movement from a room to a source surface of convective jet is determined. This measure made it possible to reduce the air velocity above surface source and the amount of harmful emissions by 2.5 times, as well as to reduce their flow into a room through an opening a shelter. These measures allow to reduce energy costs for room ventilation and improve air quality in the serviced room.

scholarly journals Theoretical and experimental substantiation of the system of local removal of harmful substances during the combustion of candles in the worship hall of Orthodox churches and cathedrals

2021 ◽  
Vol 263 ◽  
pp. 04013
Author(s):  
Alexander Eremkin ◽  
Inna Ponomareva
Keyword(s):  
Thermal Imaging ◽  
Convective Flow ◽  
Ventilation System ◽  
Air Velocity ◽  
Efficient Operation ◽  
Local Exhaust Ventilation ◽  
Convective Flows ◽  
Exhaust Ventilation ◽  
Harmful Substances ◽  
Experimental Substantiation

The analysis of the features of Orthodox churches, temples and cathedrals, elements of the design of the halls of worship, and their preservation. The types of hazards generated during the burning of candles and the parishioners and staff present are systematized. Thermal imaging surveys of convective flows formed during candle combustion were carried out. A technique for conducting experiments and a diagram of an experimental setup for measuring the temperature and air velocity in a convective jet have been developed. The diagram of the convective flow structure is presented, which consists of individual jets from each candle. The results of the study have been obtained, which make it possible to determine the area of stable convective flow and the place of installation of the exhaust hood above the candlestick, as well as the distance between the burning candles and the edge of the bottom of the umbrella. A local mechanical exhaust ventilation system with umbrellas has been developed to trap and remove harmful substances from the worship hall and provide comfortable conditions for parishioners and preserve the decoration elements of the halls. The characteristics and conditions for the efficient operation of the hoods in the local exhaust ventilation system and the factors influencing their operation are given.

Chemistry of the Gasification of Carbonaceous Raw Material

2021 ◽  
Vol 1045 ◽  
pp. 67-78
Author(s):  
Pavlo Saik ◽  
Roman Dychkovskyi ◽  
Vasyl Lozynskyi ◽  
Volodymyr Falshtynskyi ◽  
Edgar Caseres Cabana ◽  
...  
Keyword(s):  
Gas Flow ◽  
Experimental Studies ◽  
Reaction Channel ◽  
Raw Material ◽  
Gas Generator ◽  
Equal Concentration ◽  
Gasification Process ◽  
Gasification Rate ◽  
Gasification Products ◽  
Gas Flow Velocity

The paper represents the studies of the process of carbonaceous raw material gasification. The initial material is represented by bituminous coal of grade H with the carbon (C) content of 79.2-85.3 %. Experimental studies have been used to substantiate the parameters of combustible generator gases (СО, Н2, СН4) output depending on the temperature of a reduction zone of the reaction channel and gas flow velocity along its length. It has been identified that the volume of the raw material input to be used for gasification process changes in direct proportion depending on the amount of burnt-out carbon and blow velocity. The gasification is intensified in terms of equal concentration of oxygen and carbon in the reaction channel of an underground gas generator. The gasification rate is stipulated by the intensity of chemical reactions, which depend immediately on the modes of blow mixture supply. Moreover, they depend directly on the intensity of oxygen supply to the coal mass and removal of the gasification products.

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